Segmental crusher roll



H. c. POLLITZ SEGMENTAL CRUSHER ROLL Filed Oct. 17, 1955 Aug. 20, 1957 IZVZ EMZEF HAROLD C RuL/rz ZSQSAH Patented Aug. 20, 1957 SEGRIENTALCRUSlER HULL Harold C. Pollitz, Cedar Rapids, l'owa, assignor to IowaManufacturing Company of Cedar Rapids, lows, Qedsr Rapids, Iowa, acorporafion of Iowa Application October 17, 1955, erial No. 54%,905

2 Claims. (Cl. 241294) The present invention relates to the constructionof rolls adapted for use in roll type rock Crushers and the like. Moreparticularly, the present invention is concerned with the provision of anovel and substantially improved crusher roll having its peripheryformed of a plurality of impact resisting metal segments secured to acylindrical core by means of radially extending wedge bolts.

As those familiar with the art of roll crusher construction are aware,numerous attempts have been made at the construction of a simple yetstrong crusher roll for use in the reduction of stone and other similarfrangible materials. I am, of course, aware of the fact that suchattempts have included the utilization of replaceable roll segmentssecured to a central cylindrical core or hub. However, to my knowledgenone of the previously constructed crusher rolls of the segmental typehave satisfactorily provided complete alignment between the segments andthe core in a simple manner. Further, in the segmental rolls with whichI am familiar the constant impacts have a tendency to cause a looseningaction on the means securing the segments to the core with the resultthat continued operation of the device causes fatigue of the rollcomponents and ultimate failure. Since it is practically impossible todetect a loose segment during crushing operations, as a result of thenoise caused by the reduction of the rocks it is of the utmostimportance that satisfactory means be provided for absolutely preventinginadvertent loosening of the segments under crushing vibrations.

In accordance with the principles of the present invention a crusherroll is provided having a one-piece hub or core carrying a plurality ofperipheral segments secured thereto by means of radially extendingsecuring bolts. The securing bolts have a wedging relationship with thesegments and the outer ends thereof lie flush with the peripheralsurface of the crushing segments. The inner ends of the bolts arerigidly secured to an axially projecting peripheral flange on the corethereby rigidly securing, and simultaneously locating, the individualsegments to the peripheral surface of the core. A further peripheralinterlocking rib and recess are provided between the inner surface ofthe individual segments and the external peripheral surface of the coreto provide positive axial alignment between the segments and the coreduring assembly thereof.

In accordance with the principles of the present invention the segmentsof the crushing roll are constructed of extremely hard heat treatedabrasion resistant alloy steel, cast steel having a high percentage ofmanganese, or other suitable hard, wear resisting material. The wedgingbolts are constructed with shanks of heat treated steel and preferablyhave the extreme head ends constructed of hard metal similar in wearcharacteristics to the material of the segments. The heat treated boltmay, accordingly, be tightened to extreme tightness without permanentdeformation while at the same time retaining sufficient elasticity underthe tightening load to prevent loosening under the extreme vibrationsproduced by the normal crushing operation.

It is, accordingly, an object of the present invention to provide anovel and substantially improved segmental crushing roll.

Another object of the present invention is to provide novel andsubstantially simplified means for securing peripheral segments of acrushing roll to the core thereof.

Still a further object of the present invention is to provide animproved means for securing segments of a crushing roll to the corethereof in substantially perfect axial and circumferential alignment.

A feature of the invention resides in the utilization of radiallyextending securing bolts having tapered head portions for wedgingcontact with crushing roll segments and for tightening from a pointwithin the crushing roll.

Another feature of the invention resides in the utilization of aplurality of peripheral segments secured to a crushing roll core bymeans of a plurality of annular rows of radially extending bolts havingtheir heads flush with the outer peripheral surface of the roll segmentsmaking it unnecessary to remove the crushing rolls from the crusher forreplacement of a roll shell.

Still other and further objects and features of the present inventionwill at once become apparent to those skilled in the art from aconsideration of the attached drawings wherein one embodiment of thepresent invention is shown by way of illustration only, and wherein:

Figure l is a side elevational view of a segmental crushing rollconstructed in accordance with the principles of the present invention;and

Figure 2 is a cross sectional view of a crusher roll constructed inaccordance with the principles of the present invention and taken alongthe line lIIl.

As shown on the drawings:

As may be seen from a consideration of Figures 1 and 2 of the drawing,the crusher roll of the present invention comprises a core 16 keyed forrotation with a supporting shaft 11 by means of a key 12. Segments 13,14 and 15, each comprising approximately 120 of the outer circumferenceof the roll are secured to axially projecting peripheral flanges 16 and17 of the core 10 by means of annular rows of radially extending boltsgenerally indicated at 29.

Each of the bolts 26 is provided with a shank 21 and a tapered headportion 22 which cooperates with a tapered hole 23 in the respectivesegments. As may be seen from Figure 2, the segment holes 23 arepositioned in radial alignment with the somewhat larger holes 24 in thecore or hub 1d. The holes 24 are slightly radially outwardly tapered andare somewhat larger in diameter than the cylindrical portion 23a of theholes 23 in order to eliminate any possibility whatever of the taperedportions 22 of the bolts 20 from bottoming against the outer peripheryof the core 10 before the respective segment is tightly secured thereto.In view of the slight clearance between the holes 24 and the shank 21,alignment of the segments 13, 14 and 15 relative to the core 1%) issupplemented by the annular rib 25 which cooperates with an arcuate slot26 in each of the segments.

During assembly, the individual segments, such as for example segment13, are positioned in place on the periphery of the core 1% with the rib25 seated in the slot 26. The individual bolts 26 are then passedthrough the aligned holes 23 and 24 and nuts 27 are threaded into a snugposition permitting the segment 13 to seat evenly throughout its portionof the circumference of the core Preferably, all of the segments arethus snugly secured before any of the nuts 27 are tightened into theirfinal tight condition. Upon assembly of the segments to the core, theindividual nuts 27 are tightened into their final tight condition,preferably by tightening diametrically opposed nuts in sequence. Whilesuch a tightening procedure is preferred, in order to maintain thesurface of the roll in a perfectly circular form it will be understoodthat varioustightening, sequences-may be utilized without departing fromthe scope of the present invention. After the. nuts .27 have been,tightened into their final condition, lock nuts 28 are threaded intotight engagement therewith to provide a completely assembled unit.

As may be seen from Figure 2, the tapered head portions 22 of the bolts20 have a taper angle approximating 20 thereby providing tight wedgingcooperation between thehead-22 and its respective hole 23. Thisrelatively small taper provides sufficiently tight wedgi'ng action toprevent rotation. of the bolt 2% during tightening of the nuts 27 andprevents any rotation thereof during operation of the roll during rockcrushing. The shanks 21 of the bolts. 2tv are preferably constructed ofa heatrtreated steel. having a high elastic limit so that an extremetorque may be applied to the nuts 27 during the tightening operationwithout exceeding the yield point of the metal. Under such a.construction, the resiliency of the metal in the bolt shanks 21 willprovide a constant force tending to prevent rotation of the nuts 27 inthe loosening direction and accordingly, in view of the non-rotatabilityof the bolt head 22, it. has been found that the roll segments of thepresent invention maintain their rigid association with the core 16)through long periods of hard usage. While self-loosening of the bolts2%} is, therefore, substantially impossible, it will be readily apparentthat the crusher roll of the present invention may readily bedisassembled by striking the individual securing bolts 2%} from theinner ends thereof with a soft metal hammer or the like after looseningthe nuts 27 and 28. In this manner, damaged segments may readily bereplaced.

The individual segments 13, 14- and 15 are preferably constructed of anabrasive resistant, hard material, such as for example cast steel havinga relatively high manganese content, such as for example on the order of12% to 14%. This material is admirably suited to crusher rolls,especially when supported by a plain cast steel core such as that shownat 19. The individual bolts 2% are likewise preferably provided withends 22a constructed of a material having extreme abrasion resistanceand impact resistance. This material may be welded to the remainder ofthe bolts, by means of resistance welding or similar operation beforethe tapered portion of the head 22 is machined. As a result of theextreme wear resistance of the end portion 22a of the bolt 20deterioration thereof during crushing is prevented andat the same timethe extreme toughness and resiliency of the heat treated shank portionof the bolt prevent any tendency to become loose. One material that hasproven satisfactory for use in the end portions 22a is the materialcommercially known as Stoodite, a hard ferrous alloy containingapproximately 35% chromium.

it will, of course, be apparent to those skilled in the art thatvariations and modifications may be made relative to the structurehereinabove set forth without departing from the scope of the novelconcepts herein disclosed. Accordingly, it is my intention that thescope of the present invention be limited solely by that of thehereinafter appended claims.

I claim as my invention: 1. A crusher roll comprising a core having aperipheral surface with a plurality of radially extending bores therein,an arcuate segment having a contour cooperating with said surface andbeing constructed of extremely hard, wear resisting material, avplurality of radial bores in said segment for alignment with saidsurface bores, each of said segment bores having a radially outwardlyclearing taper, means for aligning and securing said segments to saidcore comprising a bolt for each of said aligned set of bores, each saidbolt having an enlarged tapered head for cooperation with said outwardlyflared taper and a shank extending inwardly of said peripheral surfacefor cooperation with a retaining member, said bolt head having itsexternal surface constructed of hard Wear resisting material and itsshank constructed of tough high tensile strength material whereby theouter surface of said roll is a continuous, hard wear resisting surfaceand whereby substantial stress may be applied to said bolt shank tomaintain said segment under tension against said peripheral surface,said means for aligning and securing said segment to said coreadditionally comprising an annular peripheral rib on said core and acooperating arcuate slot in said segment and each said bolt shank.having a diameter less than the diameter of the radially extending boresin said roll surface whereby said segment is axially aligned relative tosaid core and whereby the plurality of bolts passing through saidarcuate segment may be evenly tightened in sequence and slightperipheral shift: ing of the segment may occur to provide evenlydistributed stresses throughout the peripheral length of the arcuatesegment.

2. A crusher roll comprising a core having a peripheral surface with aplurality of radially extending bores therein, an arcuate segment havinga contour co-operating with said surface and being constructed ofextremely hard, wear resisting material, a plurality of radial bores insaid segment for alignment with said surface bores, each of said segmentbores having a. radially outwardly clearing taper, means for aligningand securing said segments to said core comprising a bolt for each ofsaid aligned set of bores, each said bolt having an enlarged taperedhead for co-operation with said outwardly flared taper and a shankextending inwardly of said peripheralv surface for co-operation with aretaining member, saidbolt head having its shank constructed of toughhigh tensile strength material whereby substantial stress may be appliedto said bolt shank to maintain said segment under tension against saidperipheral surface, saidmeans for aligning and securing said segment tosaid core additionally comprising an annular peripheral rib on said coreand a co-operating arcuate slot in said segment and each said bolt shankhaving a diameter less than the diameter of the radially extending boresin said roll surface Whereby said segment is axially aligned relative tosaid core and whereby the plurality of bolts passing through saidarcuate segment may be evenly tightened in sequence and slightperipheral shifting of the segment may occur to provide evenlydistributed stresses throughout the pe ripheral length of the arcuatesegment.

References Cited in the file of this patent UNITED STATES. PATENTSCushman July 21, 1874

